As first reported by TVLine, a hero boasting “a mysterious past and equally mysterious agenda” will drop in on the titular Legends in the already-renewed CW drama’s freshman finale (airing May 19). Only described as “a beloved superhero from the DC canon,” the character will not only provide a punctuation point for Season 1 but also a launching point for Season 2, where he will recur in a handful of episodes.

While there has been much speculation about the beloved superhero’s identity in the weeks after TVLine broke the news, we have since learned that one possibility can be ruled out: time traveler Booster Gold.